Some fuel injection systems for automotive engines have a plurality of fuel injectors each of which delivers fuel to the inlet port of an associated engine combustion chamber. In some such systems, the fuel injectors are mounted in sockets of a fuel rail which has a passage to supply fuel to the injectors; the fuel rail simplifies installation of the fuel injectors and the fuel supply passage on the engine.
In such systems, a pump supplies more fuel to the fuel supply passage than is required by the injectors, and the excess fuel is discharged through a fuel pressure regulator represented, for example, by U.S. Pat. No. 3511270. In some applications, the pressure regulator diaphragm is clamped between a sheet metal cover and a sheet metal base, and the base has a rim which is deformed over a flange of the cover to apply a clamping force to the cover and diaphragm. In other applications, the pressure regulator diaphragm is clamped between a sheet metal cover and a machined base, and screws are employed to clamp the cover and the diaphragm to the base.